Cam and push-rod machine



J.- HOLLE. CAM AND PUSH ROD MACHINE.

APPLICATION FILED JAN- 6. I9I9.

Patented May 18, 1920.

INVE/I/TUR x55 0 bafle, BY

A TI'ORlI/EIS UNITED STATES JOSEPH HOLLE, OF NEWARK, NEW JERSEY.

CAM AND rues-non MACHINE.

Specification of Letters Patent.

Patented May 18, 1920.

Application filed January 6, 1919. Serial No. 269,907.

To all whom it may concern:

Be it known that I, J osnrrr Home, a citizen of the United States, and a resident of Newark, in the county of Essex and State of New Jersey, have invented a new and Improved Cam and Push-Rod Machine, of which the following is a full, clear, and exact description. I

This invention relates to a cam and push rod mechanism for puppet-valves and other devices and has for an object an improved construction wherein a greater throw is produced by the same type of cam.

Another object in view is to provide a cam and push rod arrangement in which the push rod is offset to one side of the center of a central line drawn through the cam shaft.

A still further object, more specifically, is the provision of a cam and push rod mechanism arranged so that the push rod will engage substantially fiatwise against the face of the cam, and as the parts move the same will gradually move off the push rod on to the roller so that the push rod may return in an easy manner over the rounded rear surface of the cam. r

In the accompanying drawing:

Figure 1 is a fragmentary longitudinal sectional view showing in side elevation a push rod and cam together with a puppetvalve and part of an engine in section.

Fig. 2 is an edge view of the lower end of the push rod shown in Fig. 1.

Fig. 3 is a diagram showing the extreme lower position and the extreme upper position of the push rod.

Fig. 4 is a diagram showing an old and well known arangement of cam and push rod.

Fig. 5 is a diagram showing a push rod and cam with the push rod moved for approximately half its travel.

Referring to the accompanying drawing by numerals, 1 indicates part of an engine provided with a valve seat 2 for receiving a puppet-valve 3, said puppet-valve having a push rod 4 provided with a roller 5 at the lower end and a chamfered corner 6. The rod 4 is arranged in suitable guides, as for instance the neck portion 2 and the lower guide 4. The push rod 4 and associate parts are arranged so that the cam shaft 7 together with a cam 8 are offset. The ordinary construction now in common use is substantially similar to that shown in Fig. 4

wherein the center of the push rod is pointing toward the center of the shaft 7. The cam 8 is provided with a lifting face 9 and a return face 10, the lifting face 9 being preferably arranged as a radial line extending from the center of the shaft 7, while the surface 10 is rounded in order to engage the roller 5 at the proper time and allow the roller and the push rod to move back under the action of the usual spring 11. If desired, the surface 9 could be inclined slightly off of a radial line in order to engage in a more easy manner the lower end 12 of the rod 4. When the cam first engages the rod the parts are in the position shown in Fig. 1. After the cam has moved a certain distance the parts assume the position shown in Fig. 5. .The cam continues to move until the wheel 5 has been moved to the dotted position shown in Fig. 3, whereupon the outer end of the cam 8 will slip across the chamfered corner 6 on to the roller 5, so that the roller 5 may return in an easy manner over therounded face 10. By measuring the distance of the rise of the roller 5 in Fig. 3 for instance, and measuring the distance of the rise of the roller 5 in Fig. 4, it will be observed that the structure shown in Figs. 1, 2, 3, and 5 will produce a greater lifting action than the structure shown in Fig. 4 for the same number of degrees per revolution. In the drawing the various degrees have been prepared to show a movement of forty five degrees for one cycle of operation. The time of opening is not any greater in one form than the other, but the degree of opening is much greater, and in addition the 'valve 3 is held at an almost full open position for a longer time than is provided for by the structure shown in Fig. 4. In the structure shown in Fig. 4 the action of the cam 8 is such as to produce a pressure substantially at right anglesto the pusher rod 4", while the structure shown in Fig. 1 is such that the pressure is almost axially of rod 4 whereby an easier action is provided, less power is required and greater efficiency secured throughout.

What I claim is:

1. A mechanism of the character described, comprising a push rod having a cam engaging face at one end, and an inclined face on the side of the rod at its end, and a cam adapted to first engage the end face of the rod and then ride over said inclined face of the rod.

2. A mechanism of the character described, comprising a push rod having a cam engaging end, and a roller on the rod" having its periphery projecting beyond the side face of the rod, and a cam adapted to first engage the rod and then the roller thereon.

3. A mechanism of the character described, comprising a spring-pressed push puppet-valves comprising a rod formed with a bifurcated end, an anti friction Wheel arranged in said bifurcation but spaced from the end, and a rotatable cam positioned at one side of the push rod formed to engage the bottom of the push rod and raise the push rod to a predetermined extent, and then engage said roller so that the push rod may be returned With the roller engaging the rear face of the cam. 5. A cam and push rod mechanism for valves comprising a rod having a contact face at one end, and a chamfered corner merging into the contact face, a roller mounted on said rod near the chamfered face so that a cam passing over said end and chamfered face will slide off on to the roller, and a rotatable camhaving a contact face and an arc-shaped back, said'cam being positioned during its rotation so the contact face will engage substantially flatwise against the contact end of saidrod and will gradually move over the end of said rod and said chamfered corner until it engages said roller and then move gradually past the roller so that the rollerand the rod carryingthe same may moveback With the roller passingover theaicshaped back of said cam;

JOSEPH HOLLE. 

